CORNING – Mike Jones would watch as his grandfather left the house in coughing fits, spitting up blood in the yard — the result of decades working in a Corning-area coal mine.

Jones, now 69, lives in the quaint home his grandfather raised him in. He's become a historian, brimming with information about the once-booming mining community known as Congo, but when asked how he feels about living atop hollowed-out ground, he was skeptical.

"We've always been told the coal company wasn't supposed to go under the town," Jones said. "My understanding was that no mining was done below here."

Roughly one-seventh of Perry County earth rests on massive caverns left during coal and limestone extraction, according to Ohio Department of Natural Resources mining maps. Most of the 38,000 acres affected are in the southeastern quadrant of the county. About 8,000 acres have been subject to underground coal mining in Muskingum County.

Most of the people The Times Recorder spoke with for this story were unaware that they live above previously mined areas. Up until three months ago, James Landerman Sr. didn't know the White Cottage land he'd purchased in 1962 was directly above Johnathan Mine, a 375-acre limestone mine. Then, on March 1, a sinkhole appeared less than 40 yards from his nephew Mike Lane's home just down the street.

State and federal officials spent the next two months researching the area. They found 10 sinkholes, some hundreds of square feet in size. The research indicated that, in some portions of Johnathan Mine, more than 90 percent of the once 50-foot-thick rock bed was mined, leaving less than four feet of limestone at the roof of the caves, according to a letter issued to area residents by state mineral resource officials.

On Tuesday night, a second, massive sinkhole nearly consumed the Stiers Lane home. A portion of Lane's trailer dangled over a hollowed out portion of the hillside for two days before ODNR crews were able to drag it to safety.

Not an isolated incident

Some coal mines in Muskingum and Perry counties were abandoned more than 100 years ago, according to ODNR maps. Most were closed well before the 1970s, when the department began requiring mine operators to provide accurate, up-to-date maps of where they planned to mine. The ODNR does monthly inspections.

Mines that were closed near the turn of the 20th century are considered "too dangerous" to re-enter, and the protocol for closing mines is to seal all entry points, ODNR spokesman Mark Bruce said.

Early extraction methods were known as drifting, or drilling horizontally from the surface into a hillside. Coal and limestone are found at varied depths, although extraction seldom extends beyond 500 feet below the surface, according to a 2012 ODNR survey of abandoned mines.

Subsidence issues can occur while mining both types of sedimentary rock. In addition to the Johnathan Mine sinkholes, three mine-related subsidences — two in Muskingum County, one in Perry County — have been reported since 2011, ODNR data show.

Cheryl Blosser, historian at Little Cities of Black Diamonds in Shawnee, said southern Perry County is riddled with sinkholes, but most are found in heavily wooded areas. In 1961, a portion of Ohio 216 South in New Straitsville fell into a subsidence hole above a former coal mine, necessitating a permanent rerouting of the highway. Less than five years ago, a large subsidence was found just off Plummer Hill Road in New Straitsville.

"If you spit around here, there's a good chance it's landing on hollow ground," Blosser said. "Some of the younger generations might not know, or people who move in from away, but most do."

Extraction was done through a technique called room and pillar mining, in which pillars of rock are left in place while the surrounding material is mined. The size of the pillars varies among mines, and it was common practice for pillars to be taken out when a mine was shutting down, known as "pulling stumps," to allow for greater recovery rates, according to ODNR reports. The space directly beneath Lane's home, for instance, had no pillars, and the ones surrounding it are various shapes and sizes.

Mobile pillars also were wedged in mines to avoid collapse. For most of the 20th century, they were made of wood, Blosser said.

Who's responsible?

Jones remembers when the Congo mine was closed in the mid-1950s.

"They brought in a canary in with them," he said. "Birds are much more receptive to bad air, so when that bird died, they got out of there as fast as they could. ... It was black damp. It wasn't safe for them to be in there."

Kevin Wilson, a Congo resident, navigated the overgrown wood trail to the entrance of the mine shaft. He pointed to a surprisingly ornate semicircle of stones that served as an entry point into the mine. The entrance, once at ground level, is now 20 feet high; the coal-rich ground beneath it was stripped away by heavy machinery years later.

Should a coal mine-related collapse take place near Congo, or anywhere else in the state, the state would pay to alleviate the adverse environmental effects by tapping into the Abandoned Mine Lands program, Bruce said. The program provides roughly $1 million annually through a state severance tax imposed on active strip and surface mine operators that extract coal and industrial materials, according to the ODNR website.

Thousands of acres of inhabited land in southeastern Ohio are sealed forever: too dangerous to assess, but not dangerous enough to notify residents living above. None of the people The Times Recorder contacted who are living above mined areas said they had ever received notification of prior mining operations.

State officials have no way of knowing if the archaic mine maps, many drawn by hand a century ago, cover the full extent of mining operations here.

For Jeff Stickdorn, a Shawnee native who lives on the edge of two abandoned underground mines — Shawnee Coal Co. and Claycraft Co.— there's no doubt in his mind that the ground beneath him is hollow.

"Oh, they were right underneath us," Stickdorn said on his West Street porch. "They branched out. There was no one to regulate them. But I wouldn't say I worry about it. I don't fear a collapse. What good would that do?"